Optical pyrometer.



No. 793,970. PATENTED JULY 4:, 1905,

' IL WANNER.

OPTICAL PYRUMETERR APPLICATION FILED AUG. 26, 19M.

2 SHEETE-EHEET 1.

WWMA/ IPATENTED JULY 4, 1905.

H. WANNER. OPTICAL PYROMETER.

APPLIJATION FILED AUG, 26, 1904.

2 SHEETS-SHEET 2.

[NVE/VTOR M W404 fla WITNESSES:

all C) i fi aten'teci only at, llitlltlfi.

SPJL'JCIFICAIFIUM forming; part of Letters Patent No. 793,970, dated July t, 1905.

Application iileil August 26, 1904;. Serial No. 222,303.

Be itlqnown thatl ll nlnmou Vi aua'nn, h )ad master. a citizen of the tierman timpire, residing at i l aldhausim, 11 air l'lanover, i' rovincaml i'lanover, l lmpireol tiermanv, have invented certain new and useful l'mpriwements in Uptiral livrmncters; and :l do hereby declare the :liollowim; to be a Full, cle: r and exact description oi the invention, such as will enable others skilled in th 3 art to which it appertains to make and use the same.

'lhis invention relates to an optic: ll pvrometer.

The object ol my invention is to provid 2 an optical p vrometer in which from a standard lamp of predetermined intensity an artilicial lield oi light is produced whose ii'itensitv has a known relation to thatol' the standard lamp, said artilicial licld cl light being made equal in intensity to that of the light from the incainlesecnt body whose temperature is to be dctermineih this temperature being determined from suitable e aduatioi'is which indicate the relation bitwcen the intensity of the artil'icial iield of light and the intensity of the stai'idard lamp.

i i ith this generil object in view an apparatus cmbodying my invention comprises a stamlard lamp, means for polarizing the light from said lamp, adjustable m'ians lor varying the intensity ol'' the said polarized light, i'uechanism 'lor indicating the adjustment of said adjustable in urns, and m Bans ior bringingr the light from the incaralescent body and the polarized light into juxtaposition.

ilwinp' to the tart that lie'hts ot equal intensity lrom different sources may have difl'ercnt color 'alues, which increases the dillicultv of determining when the light lrom the incandescent body and the artiiicial held of light -viz. the polarized lip'lit havc the same intensity in Y appa atus :lso provided with means forgiving th 2 same color to both lields oi ligllllk-"vlfl, that from the illCZtl'ltlOSCODll body and the artificial lield.

'lhe preilerred emlnaliment oi my invention will now be described in connection with the accompanying d 'awings in which llfiggure i is a central sectional view oi a 1,

l l roiiuetcr embodying my ll'lVCHtlOl'l; the. 2 a

l l l l l l l l side elevation: and hip. 3 a section on the line 3 3, Fig. 'l.

in thesedrawings, it is a sight-tube having both ends provided with caps A A the termer of which has an aperture u, through which the light l rom the incandescent body enters the instrmnent. in the tube a is located a lens A arranged to bringthe rays tIOlii the incai'idescont body into parallelism.

l is a diaphragm having an opening/i and in lront oi this diaphragm is a lens 1/. 'Vlhe an) it of the tube in is an QXU-OiKlilliQ' w, which is covered b,va plate of colored glass prelerablv red. at right angles to the tube A and opening into the same is a light-tube it having its outer end closed. To the end oi this tube l; nearest the tube A is secured a dial w, having; suitabli uraduations, as explained hereinafter. The tube ii prel'e ably is reduced in diamete beyond the dial a and surrounded by an alidade tube or collar U, which carries an alidade or index n and is rotatable upon the lamp-tube P. in the lamptube is mounted agroi1ml-glass plate /1, and in the space between said plate and the outer end ol the tube is placed a standard lamp which is movable toward and From said plate a by means oi a screw whose head extends outside the lamp-tube. at l is indicated a suitable polarizing device consisting in the present instam're ot a Nicols prism. The alidade collar or tube U is 'n'ovided with a stud or pin 1/, which extemls inward through a slot in the wall oi the lamp-tube l and :ar rics means for modifying" the polarized light 'tlOlH the p larizer t, this means consisting in the present case cl an analyzersuch l'or example as (he i iicol s prism fit the inner end oi the lamp-talus it is mounted a lens in, and in thc sight-tube ill opposite the lamptube there is located a iotal rcllection prism c.

The principle of ope 'ation of the appi'iratns is as follows: 'lhelight from the lamp r passing' through the piiilarizer /i is polarized, and

when the z'malyzer Us in its proper zero position the said polarized lie'htnpasses through said analyzer substantially runnialilicd and l alls upon the lens on which brings the rays of polarized light into ntrallelism and pro jects them upon the prism c, which reflects said rays into about one-half of the opening f in the partition F, thereby producing an illuminated field covering about one-half of the said opening. By rotating the alidade-collar O theanalyzeri is rotated, thus modifying the intensity of the polarized light which falls upon the prism c and as a result modifying the intensity of the field of light projected into the opening f. The alidade 0 will indicate upon the dial '22 the amount of rotation of the analyzer .7. The alidade v and dial 1/ are so adjusted with reference to each other that the zero-graduation of the dial will be indicated by the alidade when the analyzer is in the same relative position axially as the polarizer, as will be fully understood by those skilled in the art. In order to standardize the light, the analyzer is set in its zero position, and a known standard lamp, such as an amylacetate lamp, is placed opposite the opening a of the sight-tube. The light from said known standard lamp passes through the lens 7/, and thereby its rays are brought into parallelism. One-half of said rays, or thereabout, travel past the prism 0 and illuminate that half of the opening f which is not illuminated by the polarized light. By examining the two fields of light in the opening?" by applying the eye to the opening a it is possible to adjust the lamp of the instrument toward or from the glass plate 7/ by means of the screw '1' until the two fields of light in the opening f are of equal intensity. Upon this beingdone the lamp may be considered as standardized.

To use the apparatus for determining temperature, the incandescent body whose temperatureis to be determined is viewed through the sight-tube A, the light from said incandescent body falling through the opening a and the lens 6 and forming a field of light in the openingf', while the polarized light also forms a field of light in said openingf, the two fields lying side by side or slightly overlappingthat is, lying in juxtaposition. By rotating the alidade-collar O, and thereby the analyzer Z, the polarized light from the prism Z is suitably modified, so that the artificial field of light formed in the half of the openingfis modified in intensity until it appears to the eye at of the same intensity as the field of light from the incandescent body. Upon this condition being attained the temperature of the incandescent body can be determined by reading the graduations upon the dial 1/, which preferably instead of being graduated in degrees of angle is marked with the different temperatures corresponding to the difi'erent angles of rotation of the analyzer By this means a direct reading of thetemperature is possible. It will be observed that in this construction a standard source of light is employed and that from this polarized light is produced which can be modified in intensity by the adjustment of the analyzer and that in this way an artificial field of light is produced in juxtaposition to the field of light from the incandescent body, the said artificial field of polarized light being modified by the adjustment of the analyzer until it appears of equal intensity with the field of light from the incandescent body, whereupon the temperature can be read from the dial '22.

Having thus fully described the invention, what I. claim is 1. In an optical pyrometer, the combination, with a source of polarized light of ascertainable intensity, and means for producing therefrom an artificial field of light whose intensity relative to thatof the polarized light is known, of means for bringing into juxtaposition to said artificial field of light, a field of light from the incandescent body whose temperature is to be determined.

2. In an optical pyrometer, the combination, with a source of polarized light of ascertainable intensity, of adjustable means for modifying the intensity of said polarized light, mechanism for indicating the adjustment of said modifying means, and means for bringing a field of said polarized light into juxtaposition with a field of light from the incandescent body whose tem iierature is to be determined.

3. In an optical pyrometer, the combination with a standardized source of light, means for polarizing the same, and means for producing with said polarized light an artificial field'of light, of an adjustable analyzer arranged to modify the intensity of said artificial field, means for indicating the adjustment of said analyzer and means for bringing a field of light from the incandescent body under examination into juxtaposition with the said artificial field of light.

4:. In an optical pyrometer, the combination, with apolarizer and an analyzer, one of which is adjustable relative to the other. means for indicating the relative adjustment of the polarizer and analyzer, a source of light arranged to throw its light through the polarizer and analyzer, and means for bringing into juxtaposition a field of the polarized light and a field of light from the incandescent body to be examined.

In testimony whereof I affix my signature to this specification in the presence of two witnesses.

HEINRICH. IVANNER.

Witnesses:

Lnoxonu Rason', ANNA D'rrrn'n. 

